provision for dungeon creatures to be friendly
could be cool.
I tried giving a monster ATTACK_METHOD_HEAL
but it didn't seem to do anything.
If this worked you could have a creature who
when you went up to it, would heal someone in the party.
You could confine it to a certain area with monster teleporters
or you could just let it follow the party around healing them!
That could possibly result in it blocking in dead ends where
you would have to kill it though

The next stage along this line of thinking is having a monster
which follows you, but then attacks enemy monsters when encountered.
Any other ideas what a friendly creature might do?